Labor says AFP raid is an extraordinary attack on the Parliament

CANBERRA -- The Australian Federal Police (AFP) have searched email servers at Parliament House over leaked classified documents showing a cost blow out with the National Broadband Network (NBN).

It's forced the Prime Minister Malcolm Turnbull to defend the integrity of the AFP, after one of the alleged subjects of the search, Labor frontbencher Stephen Conroy, declared the AFP was being used to intimidate people.

Opposition Leader Bill Shorten has also stated his view at the National Press Club that the leak "complaint was triggered from within the government."

The search warrant indicates the AFP is searching for correspondence relating to several Labor staffers, the NBN, NBN Co, several classified plans and briefings, as well as media organisations including The Australian, The Australian Financial Review, delimiter.com.au and the ABC.

Mr Turnbull has called on Opposition Leader Bill Shorten to "pull Senator Conroy into line" over his comments, saying it was an "outrageous suggestion" that the AFP was not acting independently of Government.

"He knows absolutely as well as we do that the AFP are thoroughly independent of the Government, there is no political direction at all," he told reporters in Sydney.